scholarly journals The relationship between protein turnover and energy balance in lean and genetically obese (ob/ob)mice

1979 ◽  
Vol 42 (2) ◽  
pp. 185-199 ◽  
Author(s):  
B. G. Miller ◽  
W. R. Otto ◽  
R. F. Grimble ◽  
D. A. York ◽  
T. G. Taylor
Keyword(s):  
Protein Synthesis ◽  
Energy Balance ◽  
Dietary Intake ◽  
Protein Content ◽  
Energy Intake ◽  
Total Protein ◽  
Protein Turnover ◽  
Obese Mice ◽  
Tissue Protein ◽  
The Relationship

1. Groups of lean and genetically obese (ob/ob) mice were adapted to varying energy intakes and the rates of total protein turnover in liver, gut and kidney were measured.2. Lean mice gained less weight when fed above maintenance and lost less weight when fed below maintenance than obese mice.3. Hepatic protein turnover (mg/d) was sigmoidally related to digestible energy intake in lean mice but showed no significant changes with dietary intake in obese mice.4. The changes in protein turnover resulted from changes in both the half-lives of protein synthesis and catabolism and in tissue protein content.5. In the lean mice, protein turnover in kidney and gut was not significantly changed with increasing energy intake until the highest level was reached.6. The findings suggest that protein turnover may be an important cycle for the regulation of energy balance in mice and that this cycle is impaired in the genetically obese (ob/ob) mice.

A New Technique for Measuring Protein Turnover in the Gut, Liver and Kidneys of Lean and Obese Mice with [3H]Glutamic Acid

1978 ◽  
Vol 54 (4) ◽  
pp. 425-430
Author(s):  
B. G. Miller ◽  
R. F. Grimble ◽  
T. G. Taylor
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Turnover ◽  
Total Radioactivity ◽  
Obese Mouse ◽  
Obese Mice ◽  
Tissue Protein ◽  
Liver And Kidney ◽  
A New Technique ◽  
Kidney Liver

1. We have measured the incorporation of an intraperitoneal injection of [3H]glutamate into the protein of the gut, liver and kidney of lean and obese siblings of the genetically obese mouse. 2. Recycling of the 3H was minimized by using glutamate labelled at the C-2 position. Loss of label from the amino acid pool by transamination and deamination was rapid, with a half-life of 4 h. 3. In tissue protein the amino acid showing the highest 3H radioactivity was glutamate. 4. The half-lives for protein synthesis and catabolism were calculated from the decay curves of both specific and total radioactivity of [3H]glutamate in tissue protein. No significant differences were found between kidney, liver and gut in lean and obese mice.

Total protein content and protein synthesis within pre-elongation stage bovine embryos

1998 ◽  
Vol 50 (2) ◽  
pp. 139-145 ◽  
Author(s):  
J.G. Thompson ◽  
A.N.M. Sherman ◽  
N.W. Allen ◽  
L.T. McGowan ◽  
H.R. Tervit
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Total Protein Content ◽  
Bovine Embryos

Changes in protein during development of Triturus embryos

Development ◽  
1973 ◽  
Vol 30 (3) ◽  
pp. 647-659
Author(s):  
Hiroshi Imoh ◽  
Tsutomu Minamidani
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Sodium Carbonate ◽  
Dna Content ◽  
Total Protein ◽  
Soluble Protein ◽  
Nuclear Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Tail Bud ◽  
Stage Of Development

The present paper reports basic data on DNA content, protein content, and protein synthesis in Triturus pyrrhogaster embryos during development from cleavage to the hatching stage. Except for measurements of DNA and total protein contents, embryos were labeled with sodium carbonate-14C for 10 h and fractionated into embryonic cell components, i.e. cytoplasmic mass, yolk and pigment granules, and nuclei, in a discontinuous density gradient of sucrose. The protein content and the radioactivity incorporated into protein were measured in each fraction. Those fractions combining protein soluble in buffer at pH 8·3 and in 0·25 N-HCl were further studied with polyacrylamide gel electrophoresis. In the newt embryo, four stages of active DNA increase were observed when cultured at constant temperature; they were gastrula, neurula, late tail-bud, and before-hatching stages. Total protein per embryo decreased from 3 to 2 mg during the development studied. The content of cytoplasmic soluble protein per embryo was low and constant throughout development. Synthesis of the fraction was observed at the earliest stage of development studied though the rate was not high and specific activity of the soluble protein increased during development. Qualitative changes in the newly synthesized protein were observed. With the yolk fraction, synthesis of protein, other than from probable contamination with the cytoplasmic fraction, was not detected and a detailed description was omitted. Changes were observed at two stages of development in the synthesis of nuclear protein soluble in buffer at pH 8·3, the first at gastrulation and the second at late tail-bud stage. The change at gastrulation seemed to be the start of syntheses of the nuclear soluble proteins, while quantitative enhancement rather than qualitative change was noticed at late tail-bud stage. Most of the nuclear protein soluble in 0·25 N-HCI was histone. The histone content increased in accordance with increase in the DNA content and the rate of DNA accumulation was accompanied by proportionate incorporation of radioactivity into histone. Among histone fractions, unique behaviour of the very lysine-rich histone was observed. The availability of [14C]sodium carbonate in rough estimations of protein synthesis in embryos and significance of the data obtained have been discussed.

AMINO ACID UTILIZATION AND PROTEIN SYNTHESIS IN THE OVINE FETUS IN UTERO

1984 ◽  
Vol 64 (5) ◽  
pp. 287-288 ◽  
Author(s):  
D. D. KITTS ◽  
A. L. SCHAEFER ◽  
C. R. KRISHNAMURTI
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Key Words ◽  
Protein Turnover ◽  
In Utero ◽  
Intermediary Metabolites ◽  
Tissue Protein ◽  
Amino Acid Utilization ◽  
Ovine Fetus

The utilization of amino acids in chronically catheterized ovine fetuses was measured by isotopic and nonisotopic procedures. Extensive incorporation of amino acid carbon into tissue protein was accompanied by high protein turnover and recycling rates of amino acid carbon. Alternative utilization of amino acids included oxidation and conversion into intermediary metabolites. Key words: Amino acids, utilization, fetus

Effect of dietary protein content on tissue protein synthesis rates in Zucker lean rats

1999 ◽  
Vol 19 (7) ◽  
pp. 1017-1026 ◽  
Author(s):  
Rosa Masanés ◽  
José-Antonio Fernández-López ◽  
Marià Alemany ◽  
Xavier Remesar ◽  
Inmaculada Rafecas
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Dietary Protein ◽  
Tissue Protein ◽  
Tissue Protein Synthesis

Glucocorticoid-induced skeletal muscle atrophy in vitro is attenuated by mechanical stimulation

1992 ◽  
Vol 262 (6) ◽  
pp. C1471-C1477 ◽  
Author(s):  
J. A. Chromiak ◽  
H. H. Vandenburgh
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Weight Lifting ◽  
Mechanical Activity ◽  
Synthesis Rate ◽  
Protein Synthesis Rate

Glucocorticoids induce rapid atrophy of fast skeletal myofibers in vivo, and either weight lifting or endurance exercise reduces this atrophy by unknown mechanisms. We examined the effects of the synthetic glucocorticoid dexamethasone (Dex) on protein turnover in tissue-cultured avian fast skeletal myofibers and determined whether repetitive mechanical stretch altered the myofiber response to Dex. In static cultures after 3-5 days, 10(-8) M Dex decreased total protein content 42-74%, total protein synthesis rates 38-56%, mean myofiber diameter 35%, myosin heavy chain (MHC) content 86%, MHC synthesis rate 44%, and fibronectin synthesis rate 29%. Repetitive 10% stretch-relaxations of the cultured myofibers for 60 s every 5 min for 3-4 days prevented 52% of the Dex-induced decrease in protein content, 42% of the decrease in total protein synthesis rate, 77% of the decrease in MHC content, 42% of the decrease in MHC synthesis rate, and 67% of the decrease in fibronectin synthesis rate. This in vitro model system will complement in vivo studies in understanding the mechanism by which mechanical activity and glucocorticoids interact to regulate skeletal muscle growth.

scholarly journals Personalized Protein Supplementation Improves Total Protein, Leucine, and Energy Intake in (Pre)Sarcopenic Community-Dwelling Older Adults in the ENHANce RCT

2021 ◽  
Vol 8 ◽  
Author(s):  
Lenore Dedeyne ◽  
Jolan Dupont ◽  
Sabine Verschueren ◽  
Katrien Koppo ◽  
Jos Tournoy ◽  
...  
Keyword(s):  
Older Adults ◽  
Dietary Intake ◽  
Energy Intake ◽  
Body Mass ◽  
Dietary Protein ◽  
Total Protein ◽  
Protein Intake ◽  
Protein Supplementation ◽  
Community Dwelling ◽  
Community Dwelling Older Adults

Recommendations concerning protein quantity, source, and leucine intake for older adults are difficult to reach by regular dietary intake. This randomized clinical trial assesses in sarcopenic community-dwelling older adults (i) the regular (non-supplemented) daily protein and leucine intake; and (ii) the effect of personalized protein supplementation (aiming for an evenly distributed total protein intake of 1.5 g·kg−1·d−1 of body mass, accounting for energy intake) on regular and total (dietary and supplemental) intake. A preliminary feasibility study in participants of the ongoing Exercise and Nutrition for Healthy AgeiNg (ENHANce) study was performed with the objective to assess the intake and distribution of regular dietary protein and leucine, protein source and energy intake in (pre)sarcopenic community-dwelling older adults. Moreover, this study aimed to assess if personalized protein supplementation was feasible without negatively affecting regular dietary intake. ENHANce (NCT03649698) is a 5-armed RCT that assesses the effect of anabolic interventions on physical performance in (pre)sarcopenic older adults. In August 2019, n = 51 participants were included in ENHANce with complete available data on dietary intake at screening and thus eligible for inclusion in present analysis. Of these, n = 35 participants completed the intervention period of ENHANce at the moment of analysis, allowing an exploration of the effect of supplementation on regular dietary intake. The regular dietary protein intake of 51 (pre)sarcopenic adults (73.6 ± 6.5 years) was 1.06 ± 0.3 g·kg−1·d−1 of body mass. Protein supplementation (n = 20) improved total protein intake to 1.55 ± 0.3 g·kg−1·d−1 of body mass (P < 0.001) without affecting regular dietary protein (P = 0.176) or energy intake (P = 0.167). Placebo supplementation (n = 15) did not affect regular dietary protein intake (P = 0.910) but decreased regular dietary energy intake (P = 0.047). Regular leucine intake was unevenly distributed over the day, but increased by supplementation at breakfast (P < 0.001) and dinner (P = 0.010) to at least 2.46 g leucine·meal−1, without reducing regular dietary leucine intake (P = 0.103). Animal-based protein intake—the main protein source—was not affected by supplementation (P = 0.358). Personalized protein supplementation ensured an adequate quantity and even distribution of protein and leucine over the day, without affecting regular dietary protein or energy intake.

Protein synthesis and degradation in flight muscles of adult crickets (Gryllus bimaculatus)

1995 ◽  
Vol 198 (5) ◽  
pp. 1071-1077 ◽  
Author(s):  
T Gomi ◽  
T Okuda ◽  
S Tanaka
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Muscle Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Adult Life ◽  
Total Protein Content ◽  
Gryllus Bimaculatus ◽  
Flight Muscles

The development and degeneration of the flight muscles in adult crickets, Gryllus bimaculatus, were studied (1) by determination of the total protein content, (2) by SDS one-dimensional polyacrylamide gel electrophoresis (SDS­PAGE) of muscle protein and (3) by in vitro culturing of the muscle. The total protein content of the dorso-longitudinal muscle (DLM) and metathoracic dorso-ventral muscle (DVM) increased during the early days of adult life in both sexes. This high protein content was maintained for at least a further 10 days in some individuals, while in others it declined to a low level. Mesothoracic DVMs in males also showed an increase in protein content after adult emergence but did not undergo histolysis, whereas those in females showed no significant temporal change in protein content. Removal of hind wings or artificial de-alation was found to be useful in inducing degeneration of DLMs and metathoracic DVMs. This treatment also stimulated ovarian development in females. An analysis by SDS­PAGE provided no evidence for new protein synthesis prior to or during flight muscle degeneration. A high rate of [3H]- or [35S]methionine incorporation was observed in DLMs taken from newly emerged adults, but, in intact crickets, the rate declined rapidly during the first 3 days of adult life, a pattern consistent with that obtained from the measurement of total protein content. Compared with DLMs removed from intact crickets, DLMs taken from de-alated crickets showed reduced rates of protein synthesis during in vitro culturing. This, together with the onset of protein degradation, appears to cause the rapid decrease in total protein content of the muscle in de-alated crickets.

scholarly journals Dietary lysine deficiency greatly affects muscle and liver protein turnover in growing chickens

1996 ◽  
Vol 75 (6) ◽  
pp. 853-865 ◽  
Author(s):  
S. Tesseraud ◽  
R. Peresson ◽  
J. Lopes ◽  
A.M. Chagneau
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Pectoralis Major Muscle ◽  
Pectoralis Major ◽  
Translational Efficiency ◽  
Liver Protein ◽  
Deficient Diet ◽  
Principal Mechanism ◽  
Tissue Protein

We analysed the respective influences of age and lysine deficiency on skeletal muscle and liver protein turnover. Growing male broilers were fed ad libirum on isoenergetic diets containing 2OO g crude protein/kg which varied in their lysine content (7·7 or 10·1 g/kg). Fractional rates of protein synthesis (FSR) were measured in vivo in the liver and the pectoralis major muscle of 2-, 3- and 4-week-old chickens (flooding dose of l-[143H]phenylalanine). Fractional rates of proteolysis (FBR) were estimated for the same tissues as the difference between synthesis and growth. Over the 2-week period liver FSR and FBR were unchanged, whereas muscle FSR decreased with age. This developmental decline was related to the lower capacity for protein synthesis (Cs) without any modifications of the translational efficiency. Whatever the age, lysine deficiency resulted in significant decreases in body weight, tissue protein content and tissue protein deposition, apparently because of reduced amounts of proteins synthesized. We recorded a difference in the response of the two tissues to lysine deficiency, the pectoralis major being more sensitive than the liver. When comparing birds of the same age, liver FSR and FBR were not modified by the diet, where as muscle FSR, Cs and FBR were higher in chicks fed on a lysinc-deficient diet than in the controls. Conversely, when chicks of similar weights were compared, the main effect of the dietary deficiency was an increase in muscle FBR. The results suggest that lysine deficiency not only delayed chick development so that protein turnover was affected, but also induced greater changes in metabolism. Thus, the principal mechanism whereby muscle mass decreased appeared to be a change in FBR.

scholarly journals Castration alters protein balance after high-frequency muscle contraction

2017 ◽  
Vol 122 (2) ◽  
pp. 264-272 ◽  
Author(s):  
Jennifer L. Steiner ◽  
David H. Fukuda ◽  
Michael L. Rossetti ◽  
Jay R. Hoffman ◽  
Bradley S. Gordon
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Protein Content ◽  
High Frequency ◽  
Muscle Contractions ◽  
Protein Balance ◽  
Fasted State ◽  
Mtorc1 Signaling ◽  
Potential Contributor ◽  
The Relationship

Resistance exercise increases muscle mass by shifting protein balance in favor of protein accretion. Androgens independently alter protein balance, but it is unknown whether androgens alter this measure after resistance exercise. To answer this, male mice were subjected to sham or castration surgery 7–8 wk before undergoing a bout of unilateral, high-frequency, electrically induced muscle contractions in the fasted or refed state. Puromycin was injected 30 min before euthanasia to measure protein synthesis. The tibialis anterior was analyzed 4 h postcontraction. In fasted mice, neither basal nor stimulated rates of protein synthesis were affected by castration despite lower phosphorylation of mechanistic target of rapamycin in complex 1 (mTORC1) substrates [p70S6K1 (Thr389) and 4E-BP1 (Ser65)]. Markers of autophagy (LC3 II/I ratio and p62 protein content) were elevated by castration, and these measures remained elevated above sham values after contractions. Furthermore, in fasted mice, the protein content of Regulated in Development and DNA Damage 1 (REDD1) was correlated with LC3 II/I in noncontracted muscle, whereas phosphorylation of uncoordinated like kinase 1 (ULK1) (Ser757) was correlated with LC3 II/I in the contracted muscle. When mice were refed before contractions, protein synthesis and mTORC1 signaling were not affected by castration in either the noncontracted or contracted muscle. Conversely, markers of autophagy remained elevated in the muscles of refed, castrated mice even after contractions. These data suggest the castration-mediated elevation in baseline autophagy reduces the absolute positive shift in protein balance after muscle contractions in the refed or fasted states. NEW & NOTEWORTHY In the absence of androgens, markers of autophagy were elevated, and these could not be normalized by muscle contractions. In the fasted state, REDD1 was identified as a potential contributor to autophagy in noncontracted muscle, whereas phosphorylation of ULK1 may contribute to this process in the contracted muscle. In the refed state, markers of autophagy remain elevated in both noncontracted and contracted muscles, but the relationship with REDD1 and ULK1 (Ser757) no longer existed.

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